I got retwittered for saying
Fear the man who says, "If you have nothing to hide, you have nothing to fear."
This saying struck a chord with some people. Let me strum that chord for a minute. Let me parse the reasoning.
The speaker is key here: Focus upon the one who says, "If you have nothing to hide, you have nothing to fear." He decides. He decides! He thinks he has a right to know your business and then to judge, after the fact, whether you had anything to hide. But what gives him any such right?
The thing spoken implies a forceful person speaking, who will take anything he is denied. That is not America. That is, indeed, what each and every word in the Bill of Rights seeks to avoid.
Legal questions of the right to privacy are somewhat complicated by prior rulings, which sometimes make things more complicated than they need to be. "Hard cases make bad law." But in principle you have, supposedly at least, the right to be left alone, absent some probable cause to bother you. It is easy to discern, today, a penumbra of privacy where it is politically convenient, but impossible otherwise.